A Tail of Histone Acetylation and DNA Recombination

To generate the huge diversity of antigen receptors expressed on T and B cells, the cell has come up with an elegant recombination dance between a series of V, D, and J gene segments that can be spliced together in numerous permutations. But how this recombination is regulated is not clear. Now, in a Perspective, Schlissel explains new findings (McMurry and Krangel) showing that histone acetylation correlates with V(D)J recombination. Selective addition of acetyl groups to histone proteins (components of nucleosomes that are the structural beads in chromatin around which the DNA is wound) is believed to alter the packaging of chromatin. In areas where the chromatin structure is relaxed, the new work suggests that recombinase enzymes can slide into the chromatin and cleave and splice the V, D, and J genes in this region.